.flex {
  display: flex;
  align-items: center;
}
.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}
.flex-between{
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.hidden {
  opacity: 0;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: -1;
}
